Techniques for measuring the performance of a communication path by exchanging measurement frames between communication devices on a network are known. As an example of such techniques, there is Ethernet OAM (Operation Administration and Maintenance). FIG. 1 is a diagram illustrating a configuration to perform failure monitoring of a layer 2 network using ITU-T (International Telecommunication Union Telecommunication Standardization Sector) recommendation G. 8013/Y. 1731 OAM.
As depicted in FIG. 1, it is possible to monitor a failure to match the management segments of the network by dividing the layer 2 network monitoring period into units such as units between customer points, units of certain periods in the provider network, and/or the like. In Ethernet OAM, for every MEG (Maintenance Entity Group), which is the monitoring target group of the layer 2 network, the communication device at the end point in the MEG is set as the MEP (MEG end point). Furthermore, in the monitoring period, communication devices of intermediate monitoring points are set as MIPs (MEG Intermediate Points). The initiating MEP is the entity to initiate measurement, and a responding MEP is an entity to give a reply in response to a request message from the initiating MEP by a responding message. Such entities exist in VLAN (Virtual Local Area Network) units. Between MEPs, VLAN path normality check, performance measurement to measure the frame loss, frame delay and/or the like of each VLAN path, and/or the like are performed.
As one means for measuring frame loss using Ethernet OAM, ETH-SLM (Ethernet Synthetic Loss Measurement function) is defined in ITU-T recommendation G. 8013/Y. 1731. In ETH-SLM, when frame loss is measured, a request message is transmitted from a given MEP. The request message will be hereinafter referred to as “SLM” (Synthetic Loss Message). An MEP having received the SLM returns a response message. The response message will be hereinafter referred to as “SLR” (Synthetic Loss Reply). The transmission source MEP of SLMs calculates the number of frame losses from the number of SLMs transmitted and the number of SLRs received. Frame loss measured in this way is used to indicate the quality of the communication path. The communication provider is able to reflect the quality of the communication path on the billing system and provide services to match the quality of the communication path, to end-user.
Related art is disclosed in ITU-T G.8013/Y.1731, “OAM functions and mechanisms for Ethernet based networks”, June 2011.